Online environmental film soars in popularity, and government steps in to tamp down the buzz

BEIJING—A deeply emotive documentary on air pollution by a well-known journalist was quickly praised by a top government official, but after it drew some 100 million views online over the weekend, censors stepped in to tamp down the buzz, according to several accounts.

Produced by former state television broadcaster Chai Jing, “Under the Dome” is a bleak look at the state of the Middle Kingdom’s skies and an unhappy commentary on how government efforts to target the problem have failed.